RAD Data comm ASM-20 - Manual (Page 49)

IR-ETH Connector Options A-1
Appendix A
Ethernet Interface
This appendix:
• Describes the IR-ETH for RAD modems
• Describes the different IR-ETH connector options
• Lists the Ethernet bridge specifications
• Explains how to install and operate an Ethernet bridge.
A.1 Description
The IR-ETH is an interface module for RAD modems, used for converting the
Ethernet (10BaseT or 10Base2) electrical levels to the modem TTL levels. It also
converts the Ethernet protocol to HDLC to enable long distance transmission and
avoid the Ethernet collision limitation.
The IR-ETH includes an internal, self-learning Ethernet bridge, which enables a
high performance link between two Ethernet segments at a low transmission rate.
The low-speed HDLC transmission is sent over the link using the modem
modulation technique. It is converted back to an Ethernet signal at the remote
modem.
Figure A-1 shows a typical application using an Ethernet interface bridge. Each
modem is connected to an Ethernet network via the Ethernet Interface bridge.
MODEM MODEM
LINK
Figure A-1 Ethernet Interface Typical Application
A.2 IR-ETH Connector Options
Figure A-2 and Figure A-3 show the rear panel of ASM-20 with the IR-ETH
connector options. The IR-ETH connector for the ASM-20/R card (rack mount
version) is shown in
Figure A-4 .